accounts were compromised. Now to a search and rescue mission and a massive manhunt. Authorities trying to solve the mystery of a couple who appear to have fallen off a carnival cruise ship near the cost of australia. Police still deploying a plane and boats, hoping they can find young couple alive. MATT GUTMANs HAD THE LATEST. Reporter: On the last night of a voyage through this south pacific paradise, paul rossington and kirstin schroder splashed silently into the sea. Authorities say they plunged overboard at the mid-deck promenade, a 50-foot drop to the water, but survivable. No one noticed until their bags went unclaimed in sydney harbor. Carnival surveillance cameras captured the fall. The company says, "there is no evidence of foul play." But it is another tough headline for carnival. The coast guard is currently investigating the cruise line for six other incidents ranging from fires to ships being stuck at sea. Like the carnival "triumph," which lost power at sea in february. And the stench is horrific. Reporter: Sewage flowing down the halls with 4,000 angry passengers aboard. Then the "dream" lost propulsion -- all this after the "costa concordia" grounded in 2012, killing 32. Problems or mishaps with cruise ships are certainly more frequent than we know of. Those that we know of are impacting the sale of cruise ships. Reporter: Carnival slashed prices to $40 a night for some cruises. But despite it all, carnival says its sales remain robust. Matt gutman, abc news, miami.

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